Bibcode
DOI
Labbé, Ivo; Rudnick, Gregory; Franx, Marijn; Daddi, Emanuele; van Dokkum, Pieter G.; Förster Schreiber, Natascha M.; Kuijken, Konrad; Moorwood, Alan; Rix, Hans-Walter; Röttgering, Huub; Trujillo, I.; van der Wel, Arjen; van der Werf, Paul; van Starkenburg, Lottie
Bibliographical reference
The Astrophysical Journal, Volume 591, Issue 2, pp. L95-L98.
Advertised on:
7
2003
Journal
Citations
75
Refereed citations
67
Description
Using deep near-infrared imaging of the Hubble Deep Field-South with the
Infrared Spectrometer and Array Camera on the Very Large Telescope, we
find six large disklike galaxies at redshifts z=1.4-3.0. The galaxies,
selected in Ks (2.2 μm), are regular and surprisingly
large in the near-infrared (rest-frame optical), with face-on effective
radii re=0.65"-0.9" or 5.0-7.5 h-170
kpc in a Λ cold dark matter cosmology, comparable to the Milky
Way. The surface brightness profiles are consistent with an exponential
law over 2-3 effective radii. The Wide Field Planetary Camera 2
morphologies in Hubble Space Telescope imaging (rest-frame UV) are
irregular and show complex aggregates of star-forming regions ~2" (~15
h-170 kpc) across, symmetrically distributed
around the Ks-band centers. The spectral energy distributions
show clear breaks in the rest-frame optical. The breaks are strongest in
the central regions of the galaxies and can be identified as the
age-sensitive Balmer/4000 Å break. The most straightforward
interpretation is that these galaxies are large disk galaxies; deep
near-infrared data are indispensable for this classification. The
candidate disks constitute 50% of galaxies with
LV>~6×1010 h-270
Lsolar at z=1.4-3.0. This discovery was not expected on the
basis of previously studied samples. In particular, the Hubble Deep
Field-North is deficient in large galaxies with the morphologies and
profiles we report here.
Based on service mode observations collected at the European Southern
Observatory, Paranal, Chile (ESO programme 164.O-0612) and also based on
observations with the NASA/ESA Hubble Space Telescope, obtained at the
Space Telescope Science Institute, which is operated by AURA, Inc.,
under NASA contract NAS5-26555.